HTML to Image / Golang Reference

Constructor for the PDFCrowd API client. Initialize a new instance of the conversion client with your PDFCrowd account credentials.

You must provide both your username and API key. This establishes the authenticated connection for all subsequent conversion operations.

The output file format.

Convert a web page from a URL.

Use this as the primary method for converting web content, online documents, or any publicly accessible URL to the desired output format. Returns the conversion result as a byte array for further processing or direct use.

Convert a web page from a URL and write the conversion result directly to an output stream.

Use this when you need to handle large conversion results, integrate with streaming pipelines, or build server applications that process conversions continuously.

Convert a web page from a URL and save the conversion result directly to a local file.

Use this for simple file-based workflows, batch processing, or when you need to persist conversion output to disk. The most straightforward method for URL-to-file conversions.

Convert a local file to the desired output format.

Use this for processing files already on your system, converting uploaded documents, or batch processing local content. Returns the conversion result as a byte array for in-memory processing.

Convert a local file and write the conversion result directly to an output stream.

Use this when working with large conversion results, integrating with streaming frameworks, or building applications that need direct stream-to-stream processing.

Convert a local file and save the conversion result to another local file.

Use this for file-based batch processing, document transformation workflows, or when both input and output are file-based. The simplest method for file-to-file conversions.

Convert a string containing source content to the desired output format.

Use this for converting dynamically generated content, templates, user input, or any text-based data held in memory. Ideal for real-time content generation and API integrations.

Convert a string containing source content and write the conversion result directly to an output stream.

Use this when processing dynamically generated content with large outputs, integrating with streaming APIs, or building high-throughput web applications.

Convert a string containing source content and save the conversion result to a local file.

Use this for persisting dynamically generated content, creating documents from templates, or saving user-generated conversions. Combines in-memory source with file-based output.

Convert content from an input stream to the desired output format.

Use this when integrating with I/O pipelines, processing data from network streams or file handles, or when the source data is provided as a stream by your application.

Convert content from an input stream and write the conversion result to an output stream.

Use this when both input and output need to be streams, integrating with streaming frameworks, or building conversion services that process data in stream form throughout.

Convert content from an input stream and save the conversion result to a local file.

Use this when processing streaming uploads that need to be saved, handling network data sources with file-based output, or building services that accept stream input and produce file output.

Set the file name of the main HTML document stored in the input archive. Use this when your ZIP/TAR archive contains multiple HTML files and you need to specify which one to convert.

If not specified, the first HTML file found in the archive is automatically used for conversion.

Set the output image width in pixels.

Set the output image height in pixels. If it is not specified, actual document height is used.

Set the scaling factor (zoom) for the output image.

The output image background color in RGB or RGBA hex format. Use transparent (00000000) for PNG overlays or solid colors for web display.

Use the print version of the page if available via @media print CSS rules. Enable this when converting websites that have print-optimized styles. Many sites hide navigation, ads, and sidebars in print mode.

Produces cleaner PDFs by using the design the website creator intended for printing.

Do not print the background graphics to create printer-friendly PDFs. Use this when documents will be physically printed to save ink costs and improve readability.

Removes background colors, images, and patterns while preserving text and foreground content. Particularly useful for documents with dark backgrounds or decorative elements.

Do not execute JavaScript during conversion. Use this to improve conversion speed when JavaScript is not needed, prevent dynamic content changes, or avoid security risks from untrusted scripts.

Note that disabling JavaScript means lazy-loaded images and AJAX content will not load.

Do not load images during conversion to create text-only PDFs. Use this to significantly speed up conversion, reduce file size, or create accessible text-focused documents.

Ideal for converting documentation where images are not needed, reducing bandwidth usage, or creating lightweight PDFs for email distribution.

Disable loading fonts from remote sources. Use this to speed up conversion by avoiding font download delays, ensure consistent rendering with system fonts, or work around font loading failures.

Note that text will fall back to system fonts, which may change the document's appearance.

Use a mobile user agent when making requests to the source URL.

Specifies how iframes are handled during conversion. Use "all" to include all embedded content (videos, maps, widgets). Use "same-origin" to include only content from the same domain for security purposes. Use "none" to exclude all iframes for faster conversion and to avoid third-party content issues.

Disabling iframes can significantly improve performance and reliability.

Automatically block common advertising networks and tracking scripts during conversion, producing cleaner PDFs with faster conversion times. Filters out third-party ad content, analytics beacons, and ad network resources.

Ideal for converting news sites, blogs, or any ad-heavy content where ads distract from the main message. May occasionally block legitimate third-party content - disable if critical third-party resources are missing.

Specify the character encoding when the HTML lacks proper charset declaration or has incorrect encoding. Prevents garbled text for non-English content, especially legacy pages without UTF-8 encoding.

Set to "utf-8" for modern content, "iso-8859-1" for Western European legacy pages, or other encodings for specific regional content. Only needed when auto-detection fails and you see corrupted characters in the output.

Set the locale for the conversion to control regional formatting of dates, times, and numbers. Use this when converting content for specific regions - for example, set to "en-US" for MM/DD/YYYY dates and comma thousand separators, or "de-DE" for DD.MM.YYYY dates and period thousand separators.

Essential for financial reports, invoices, or localized content.

Set credentials to access HTTP basic authentication protected websites. Use this when converting content behind HTTP authentication, such as development servers, staging environments, or password-protected documentation.

Provide both username and password to authenticate requests. Essential for converting internal resources or protected content.

Set HTTP cookies to be included in all requests made by the converter to access authenticated or session-based content. Use this when converting pages that require login, maintain user sessions, or personalize content based on cookies.

Essential for converting member-only areas, dashboards, or any content behind cookie-based authentication. Format as semicolon-separated name=value pairs.

Enforce SSL certificate validation for secure connections, preventing conversions from sites with invalid certificates. Enable when converting from production sites with valid certificates to ensure security.

When disabled, allows conversion from any HTTPS site regardless of certificate validity - including development servers with self-signed certificates, internal corporate sites with expired certificates, or local testing environments.

Abort the conversion if the HTTP status code of the main URL is greater than or equal to 400 (client/server errors). Use this in automated workflows to catch broken URLs or authentication failures early rather than producing invalid PDFs. Ensures your system does not silently generate error page PDFs when source content is unavailable.

Abort the conversion if any sub-request (images, stylesheets, scripts) fails with HTTP 400+ errors. Use this for strict quality control when all assets must load successfully.

Do not send the X-Pdfcrowd HTTP header in HTTP requests made by the converter. Use this if your target server blocks or logs requests with this header, or for privacy when you do not want sites to know you are using PDFCrowd. Some security systems may block requests with non-standard headers.

Apply custom CSS to the input HTML document to modify the visual appearance and layout of your content dynamically. Use this to override default styles, adjust spacing, change fonts, or fix layout issues without modifying the source HTML.

Use !important in your CSS rules to prioritize and override conflicting styles.

Run a custom JavaScript after the document is loaded and ready to print. Use this to modify page content before conversion, remove unwanted elements, or trigger specific page states. The script is intended for post-load DOM manipulation (add/remove elements, update CSS, ...).

In addition to the standard browser APIs, the custom JavaScript code can use helper functions from our JavaScript library.

Run a custom JavaScript right after the document is loaded. The script is intended for early DOM manipulation (add/remove elements, update CSS, ...). In addition to the standard browser APIs, the custom JavaScript code can use helper functions from our JavaScript library.

Set a custom HTTP header to be included in all requests made by the converter. Use this to pass authentication tokens to protected sites, add tracking headers for analytics, or provide API keys for accessing private content.

Essential when converting content from APIs or internal systems that require special headers for access control.

Wait the specified number of milliseconds to finish all JavaScript after the document is loaded. Use this to ensure lazy-loaded images, AJAX content, or animations complete before conversion. Your license defines the maximum wait time by "Max Delay" parameter.

Convert only the specified element from the main document and its children. Use this to extract specific portions of a page (like article content) while excluding navigation, headers, footers, or sidebars. The element is specified by one or more CSS selectors. If the element is not found, the conversion fails. If multiple elements are found, the first one is used.

Control how CSS styles are applied when converting only part of a page. The "cut-out" option extracts the element into a new document root, which may break CSS selectors like "body > div". The "remove-siblings" option keeps the element in its original DOM position but deletes other elements, preserving descendant selectors. The "hide-siblings" option keeps all elements but hides non-selected ones with display:none, preserving all CSS context.

Wait for the specified element in a source document. Use this when specific dynamic content must be ready before conversion, avoiding unnecessary delays from a fixed JavaScript delay. The element is specified by one or more CSS selectors. The element is searched for in the main document and all iframes.

If the element is not found, the conversion fails. Your license defines the maximum wait time by the "Max Delay" parameter.

The main HTML element for conversion is detected automatically. Use this when you want to extract article or main content without knowing the exact CSS selector, automatically excluding navigation and sidebars.

Automatically enhance the input HTML to improve readability by removing clutter and reformatting content. Use this when converting web pages with excessive navigation, ads, or sidebars that distract from the main content.

Different versions (v1-v4) use progressively aggressive algorithms - start with "v1" and increase if more cleanup is needed. Ideal for converting blog posts, articles, or documentation into clean PDFs.

Set the input data for template rendering. The data format can be JSON, XML, YAML or CSV.

Load the input data for template rendering from the specified file. The data format can be JSON, XML, YAML or CSV.

Specify the input data format. Use "auto" for automatic detection or explicitly set to JSON, XML, YAML, or CSV when format is known.

Set the encoding of the data file set by setDataFile.

Ignore undefined variables in the HTML template. The default mode is strict so any undefined variable causes the conversion to fail. You can use {% if variable is defined %} to check if the variable is defined.

Auto escape HTML symbols in the input data before placing them into the output.

Auto trim whitespace around each template command block.

Set the advanced data options:

• csv_delimiter - The CSV data delimiter, the default is ,.
• xml_remove_root - Remove the root XML element from the input data.
• data_root - The name of the root element inserted into the input data without a root node (e.g. CSV), the default is data.

Turn on debug logging to troubleshoot conversion issues. Details about the conversion process, including resource loading, rendering steps, and error messages are stored in the debug log. Use this when conversions fail or produce unexpected results. The URL of the log can be obtained from the getDebugLogUrl method or available in conversion statistics.

Get the URL of the debug log for the last conversion.

Get the number of conversion credits available in your account. Use this to monitor your credit usage and implement alerts before running out of credits.
This method can only be called after a call to one of the convertXtoY methods.
The returned value can differ from the actual count if you run parallel conversions.
The special value 999999 is returned if the information is not available.

Get the number of credits consumed by the last conversion. Use this to track costs per conversion, especially for complex documents or operations that may consume multiple credits.

Get the unique job ID for the conversion. Use this to track conversions in your logs, correlate with debug logs, or reference specific conversions when contacting support.

Get the size of the output document in bytes. Use this to check file sizes before delivery, implement size-based quotas, or optimize storage allocation.

Get the version details including API version, converter version, and client library version. Use this for debugging, logging, or ensuring compatibility when reporting issues.

Tag the conversion with a custom value for tracking and analytics. Use this to categorize conversions by customer ID, document type, or business unit. The tag appears in conversion statistics. A value longer than 32 characters is cut off.

A proxy server used by the conversion process for accessing the source URLs with HTTP scheme. This can help circumvent regional restrictions or provide limited access to your intranet.

A proxy server used by the conversion process for accessing the source URLs with HTTPS scheme. This can help circumvent regional restrictions or provide limited access to your intranet.

A client certificate to authenticate the converter on your web server. The certificate is used for two-way SSL/TLS authentication (mutual TLS) and adds extra security. Use this when converting content from servers that require client certificate authentication for access.

A password for the PKCS12 file with a client certificate if the certificate file is password-protected.

Set the maximum time for loading the page and its resources. After this time, all requests will be considered successful. This can be useful to ensure that the conversion does not timeout. Use this method if there is no other way to fix page loading.

Specify the User-Agent HTTP header that will be used by the converter when a request is made to the converted web page.

Set the converter version. Different versions may produce different output. Choose which one provides the best output for your case.

Specify whether to use HTTP or HTTPS when connecting to the PDFCrowd API.

Specify the User-Agent HTTP header that the client library will use when interacting with the API.

Set a custom user agent HTTP header. It can be useful if you are behind a proxy or a firewall.

Specify an HTTP proxy that the API client library will use to connect to the internet.

Specify the number of automatic retries when a 502 or 503 HTTP status code is received. The status code indicates a temporary network issue. This feature can be disabled by setting to 0.